#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
int n,sum,i;while(scanf("%d",&n)!=EOF){ sum = 1; if(n>1 && n<30) { for(i=1; i<n; i++) { sum = 2*(sum+1); } printf("%d\n",sum); }}return 0;}
-----------------------------------------------2014 评委打分#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
int n,i;double min,max,sum,avg;double arr[100];while(scanf("%d",&n)!=EOF){ if(n>2 && n<=100) { scanf("%lf",&arr[0]);//第一次的成绩 sum = min = max = arr[0]; for(i=1; i<n; i++) { scanf("%lf",&arr[i]); if(arr[i]>max) max = arr[i]; if(arr[i]<min) min = arr[i]; sum += arr[i]; } avg = (sum - min - max)/(n-2); printf("%.2lf\n",avg); } }return 0;}
-----------------------------------------------2015 偶数求和#define _CRT_SECURE_NO_WARNINGS 1
#include <stdio.h>
int main()
{
int n,m,i,j,sum,count;while(scanf("%d%d",&n,&m)!=EOF){ for(i=1; i<=n;) { sum = 0; count =0; for(j=1; j<=m&&i<=n; j++) { sum += i*2; count++; i++; } printf("%d",sum / count); if(i<=n) printf(" "); } printf("\n");}return 0;}